docs(frontend): autonomous architectural standardization

[beginwebdev2002]

• Standardized YAML frontmatter across all frontend documentation to only include required attributes for AI-Agent context routing.
• Fixed an issue where the closing --- was joined with the last value.
• Enforced 4-step lifecycle formatting (### ❌ Bad Practice, ### ⚠️ Problem, ### ✅ Best Practice, ### 🚀 Solution) using the correct heading sizes and emojis in documents containing code patterns.
• Replaced the unsafe any keyword with unknown where applicable inside ✅ Best Practice documentation blocks to align with type safety enforcement rules.

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PR created automatically by Jules for task 3718584388165503128 started by @beginwebdev2002

[google-labs-jules]

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